The present invention relates to electromagnetic rail guns and more particularly to barrel assemblies therefore.
Various types of rail guns have been proposed for using electromagnetic forces to accelerate projectiles to high velocities and direct them toward targets. See, for example, U.S. Pat. No. 1,985,254.
A typical rail gun includes an elongated barrel which has a pair of longitudinally extending parallel conductors or rails disposed symmetrically about its longitudinal axis. The rails are connected at their rearward or breech ends to opposite terminals of a source of direct current. A circuit through the rails may be completed either by a movable conductor disposed between the rails or by a plasma arc between the rails. This results in the flow of current that generates magnetic flux between the rails, and the flux cooperates with the current in the conductor or the plasma to accelerate the conductor or plasma forward between the rails. The projectile may include the conductor or may be positioned forward of the conductor or plasma arc and driven forward thereby.
When the rail gun is fired, substantial transverse electromagnetic forces are generated which tend to push the rails apart. In addition, heat is generated by the current flow. Because relatively high current is generally necessary to achieve the desired projectile velocity, both the transverse electromagnetic forces and the heat may be of such magnitude as to cause failure of the barrel after a single firing.
Rail guns capable of rapid fire have been proposed, but removal of heat from the barrels has been a problem. When a rail gun is fired repeatedly, the barrel temperature rises with each firing unless a cooling system capable of removing heat at a very high rate is employed. In the past, rail guns have had rails with longitudinal cooling channels formed through them, but no known rail gun barrels have combined cooling systems capable of enabling rapid fire with structural support adequate to withstand the transverse forces on the rails.